This photo released by the Howard County Police shows shooting suspect Darion Marcus Aguilar, 19, of College Park, MD. Aguilar carried out the Saturday Jan. 25, 2014, attack with a 12-gauge shotgun at a skateboard shop at the Mall in Columbia in suburban Baltimore before killing himself, police said.

A woman who identified herself as the mother of the 19-year-old gunman in the Maryland mall shooting said Sunday she is dumbfounded and has no explanation for why her son would have killed two people.

Police have identified Darion Marcus Aguilar, 19, as the shooter who killed two people at a Maryland mall before turning the gun on himself, Howard County Police Chief Bill McMahon said today.

Police said Aguilar used a 12-gague shot gun during the incident and 16 shots were fired. In addition to the gun and ammunition, crude explosive devices made from flash powder and household items were found in Aguilar's backpack.

The woman spoke through a friend's cell phone this afternoon as he was parked in his car in front of their house in College Park, Md.

The friend, Ellis Cropper, told ABC's Hank Disselkamp he was on the phone with the mother of Darion Aguilar and she agreed to speak briefly to a small group of reporters through her sobs.

"I don't know what happened. I really don't," the woman said. "You can talk to any of his friends and see what a gentle person he is. He never had a gun before, never interested in guns. I don't know what happened. I just don't know what happened."

Cropper said Aguilar just got a promotion at a local Dunkin Donuts and was planning on enrolling in college

"Darion was a good kid," he said. "I don't know what happened ... Darion is quiet, kept to himself. Nice, normal, calm demeanor."

According to police, Aguilar entered the mall around 10:15 a.m. Saturday morning. Around 11:15, he entered the Zumiez store, a skateboard shop, on the mall's second level and fatally shot Brianna Benlolo, 21, of College Park, Md., and Tyler Johnson, 25, of Ellicott City, Md. Both were employees of the skateboard store.

McMahon said it wasn't clear whether the shooter knew his victims, although both Aguilar and Benlolo lived in College Park.

Aguilar then turned the gun on himself as frightened patrons ran from the area, McMahon said.

Police said they're still investigating the shooter's motive.

Police started receiving 911 calls about a possible shooting at the mall at around 11:15 a.m., and it was immediately put on lockdown, McMahon said. Police were reportedly on the scene within two minutes of the calls.

Aside from the three dead, five other people were injured. One person, who was below the Zumiez store during the shooting, suffered a gunshot wound to the foot and others had minor injuries as they ran to escape the shooting, according to police.

"All of the activity took place at one time, in one store," McMahon said.

After the crude explosive devices were found, police swept through the mall using canine units to ensure there was no other devices on the premises.